Machine fob supplying gas ok qtheb fluid under pbessube



Nov. 16 ,1926. 1,607,370

J. M. SULLIVAN MACHINE FOR SUPPLYING GAS OR OTHER FLUID UNDER PRESSURE Filed Sept. 21. 1925 jvwefl fi Johny J 1 Sullivan,

Patented Nov. 16, 1926.

JOHN M. SULLIVAN, OF CULV ER, INDIANA.

, MACHINEFOR SUPIE'LYING GAS OR OTHER FLUID UNDER PRESSURE.

Application filed September 21, 1923, Serial 'No. 663,980.

This invention has general reference to the supplying of gas or fluid under pressure and the aim is to accomplish this result more economically than has heretofore been pos sihle.

\Vhile the invention is capable of general application, it is particularly susceptible to use in the compression of gases and more es pecially gases such as are employed in refrigeration systems. As thus specifically applied, the invention makes possible of attainment still further advantages, chief among which is the increased capacity of the compressor unit of a refrigeration system.

It is therefore an object of primary iniportance to produce an improved method of compressing ammonia gas or other refrigerant whereby the weight of the handled per minute for a given piston displacement is substantially greater than in prior art compressors.

A further object is to provide acompressor for ammonia gas or other refrigerant in which a rarefaction of the gas upon admis sion to the cylinder or cylinders is substantially avoided, and in Which the compression of the gas occurs in two steps or stages without any intercooling thereof between the two steps or stages.

A general object is to produce a compress-- ing machine of large capacity requiring a relatively small amount of floor space and employing a small number of parts as compared to prior art machines and which generally is of an extremely simple character capable of being manufactured on a very economical basis.

Still another object is to produce a double acting compressor having two sets of cylinders in which one of the two cylinders com prising each set is common to the other set, thus further increasing the capacity of the machine.

I attain the objects of the invention thus generally set forth, together with other and ancillary advantages by drawing charges of the gas or other fluid'at low pressure and ten'iperatu're simultaneously into two separate cylinders, then combining the two charges into one of the two cylinders, and finally discharging under pressure the combined charge from the one cylinder; and preferably I employ for this purpose one or more pairs of sets of axially alined cylinders each having a piston therein mounted upon a common piston rod, and I provide passages connecting the two cylinders'with each other and with an inlet or suction line so that as the pistons travel in one direction the two charges are drawn into both cy1inders simultaneously from the suction line, and While the pistons travel in the opposite direction the charge in one of the cylinders passes into the other cylinder. Also I provlde one or more valved openings in the piston in thelast mentioned cylinder through which the combined charges pass so as to be compressed and discharged into the discharge line upon the succeeding strokes of the pistons in which new charges are drawn into the separate cylinders.

I have shown in the accompanying drawings a preferred form of compressor, and for convenience in the following description I will refer to the compressor as applied to a refrigeration system, although it will be understood that the invention, as aforesaid, is susceptible of general application and use wherever it is desired tosupply a gas or other fluid under pressure. Moreover, it should be understood that I do not wish to be limited to the'particular construction of the compressor herein illustrated and described, for it is contemplated that various changes may be madeby those skilled in the art without departing from the spirit and scope of the invention as expressed inthe appended claims.

Figure 1 of the drawings is a fragmentary central vertical sectional view through a compressor constructed in accordance with my invention, the view being partially diagrammatic in character. y

Fig. 2 is a similar view but showing the pistons in different positions and also illustrating two separate sources of fluid supply,

As herein shown, the compressor comprises three separate cylinders 7, 7 and 7 which are-preferably arranged in axial alinement. These'cylinders may be of any preferred relative diameters, being herein shown as equal, and each is provided with a piston mounted upon a common piston rod 8. Thus thecylinder 7, called theprimary cylinder, has a piston 9 provided with the usual packing rings 10; the cylinders 7 and 7 called the secondary cylinders, have similar pistons 11 and 12 each provided with one or more openings 13 controlled by valves 13 adapted to permit the passage of fluid through the piston as it moves in one direction but, closing as the piston moves in the opposite direction.

The several cylinders "7, 7 and? may be constructed in any suitable or preferred manner, being herein shown as separately constructed with end flanges 1 and lt whereby the several sections be bolted together and whereby the end cylinders 7 and 7 may be provided with heads 15 and 16'. Pa rtitions 17 and 18. may be clamped between the intermediate cylinder section and the two end cylinder sections, which partitions serve to; separate thevseveral cylinders, constituting-the opposite end walls of the intermediate cylinder and the inner end walls of the two end cylinders. These partitions 17; and 18 are provided with suitable stuffing boxes 19 for the piston rod 8, and the head constituting the outer end wall of the cylinder 7 is likewise provided with a 'stuffing box 20 through which the pistonrod passes for connection with a suitable source of power.

The construction of the cylinders together with their several heads as well as thecon ing with a source oi? gas orfluid supply shown in F g. lies a single pipe 24. Thus two inlet ports :21 and 21 for the intermediate cylinder are located at opposite ends there-of and the end; cylinders 7' and 7" are provided at their inner ends with ports and respectively. The ports; 22 and 23 coinu'iunicate with the pipe 24: through branches 25 and 26 respectively,

each provided with a spring controlled valve shown di grammatically at 27, and the: ports 21 and 9,1 are respectively connected by passages; 28, 28 with the inner ends of the cv nders 7 and 7 whereby to,con1mun1- cate through said cylinders with the ports 23 and 22 respectively and tfence through the branches 26- and 25, with the supply pipe 24;. Asherein shown the passages 28 and 287' are shown for conyen ence as bemg formed in diametrically opposite sides ofv the wall oi the intermediate cylinder, and

her h y ope to the nd cy ind rs 9,"

and '7 they pass through the partitions l8 and 17 respectively. Obviously the location of thesepassages may be altered at will.

The e1 cylinders and; 7)? are respecztively; p goyided with outlet or discharge portsP S) and, 30 which communicate with a discharg P har s; b a ches 2 d 33=cornrnnnicat1ng respectively with the ports 29 and and each provided with a spring controlled valve 84 arranged to prevent the inflow of gas from the discharge pipe into the cylinders. These ports 29 and 30 it will be observed, are located at the extreme I outer ends of the cylinders 72 7 The intermediate or primary cylinder 7 is arranged to act in conjunction with each of the secondary or end cylinders 7 and 7 so as to form with either of said cylinders a pair or set. so that with the construction as herein shown a double-acting effect is pr ducel.' The operation is as follows:

Referring first to Fig. 1, the pistons in the several cylinders in moving to their sextrenie left hand positions, cause the gas or other fluid to be drawn from the supply pipe 24; into the cylinder 7 through the branch pipe 25 and past the valve 27, through the port 22, a portion of the gas or fluid in the cylinder 7 passing throughthe passage 28 and inlet port 21 into the intermediate cylinder 7. At the same time the piston 9' in the inter mediate cylinder 7 operates to force a charge of fluid previously drawn into this cylinder from the cylinder 7 and inlet port 23, through the port 21 and passage 28 into the end cylinder 7 as permitted by the piston valves 13 in the piston 12. Also, the piston 11 in the cylinder 7 operates in such movement to discharge under high pressure the charges of fluid previously combined in such cylinder in the manner just described for the cylinder 7", such dis charge taking place through the port 29 and branch pipe 32 past the check valve 34: and into the discharge pipe 31.

Upon a reversal of the direction of movement of the pistons in the seve 'al cylinders, that is to say, in their travel from the positions shown in Fig. 1 to those shown in Fig. 2, similar results are obtained, viz, separate charges of fluid are drawn into the cylinders 7 and 7 through the branch pipe 26, port 28,v message 28 and port Qlgthe charge previously drawn into the intermediate cylinder 7 is combined with the charge inthe cylinder 7 through the passage 28* and the valves 13 in the piston 11;. and the charge previously combined in the cylinder 7" is separating out anddischarged into the pipeline 31 throughthe port 30 and branch pipe 33.

It will thus be apparent that as the pistons move into the positions shown in .Fig. 1, the cylinders '7' and f? constitute a pair into which charges of gas or fluid are multaneously drawnand at the same time one 01 those cylinders, viz, the end cylinder '7 constitutes a high compression cylinder from which the fluid discharged under high pressure into the, pipe line 31. Like; wise the cylinders 7 and 7 constitute a pair Whose separate charges are simultaneously being combined in the cylinder 7 for dis charge upon the reversal of the dire tion of movement of the pistons. From the .fore-- going the double acting character of the compressor will be apparent.

As hereinbefore stated, my invention is especially applicable to refrigeration systems of the compression type and more particularly to that referred to aswet (i()l]lPl'l-3 i sion systems. no z-idvantage of my invention in such a system is that the ammonia gas or other refrigerant is supplied to the two cylinders of each set or pair that is to say, the cylinders T, 7 or 7, 7 substan tially simultaneously and direct from the source of supply, it being noted that in each instance the gas pauses through the end cylinder directly into the intermediate cylinder. Preferably as shown in the case of the port 3 and passage 28, these may be arranged to communicate in close proximity so as to avoid the necessity of the gas passing entirely across the cylinder, the arrang ment of the port 22 and the corresponding end of the passage 20" being merely shown as diametrically opposite for convenience in illustration.

One of theobjections to prior compressors used in refrigeration systemsisthat the incoming is caused to pass through narrow passages between the valves and their which have previously become heated to a high temperature, with the result that the becomes rarefied and in expanding decreases the capacity of the machine. it will be observed that in accordance with the construction and arrangement which 1 have provided the gas is drawn into the high compression cylinder at a point far-- thest remote from the dischar e end of the cylinder, while the intermediate cylinder serves an auxiliary intake chamber which remains at all times at a low temperature.

The principal advantage of this arrangement will be apparent from the fact that it provides for the induction in one stroke of alarge volume of gas in a partially sat-- urated condition, which desirable because the weight of the gas drawn while in this condition into the separate cylinders is substantially greater than would be the case if the were superheated.

Furthermore, upon the closing of the intake valves, the is of course trapped in the cylinders, and because of its low temperature it tends to absorb from the cylinder walls a portion of the heat generated in the compression of the preceding charges. As a further result, therefore, the

vlemperature of the upon-compression is reduced, thus effecting a saving in the power factor. Also, the cooling of the walls prevents a sudden expansion of the succeed ing charge of gas drawn into the cylinders. It will be observed in this connection that only the outer ends of the end cylinders are subjected to the heat of the high compression, while the intermediate cylinder is at no time subjected to the heat of the highly compressed gas. I

One type of compressor in coum'ron use is that known as the compound compres or, In all of such compressors the gas is compressed in two separate stages, first in one cylinder and then in another, the temperature of the gasbeing reduced between the two stages byan intercooling means. Such intercooling means is objectionable became of its first cost as well as because of the high cost of operation especially if it be made effective to reduce the gas to its initial temperature without a corresponding reduction in pressure. It will be observed that by my construction and arrangement such an intercooling means may be eliminated, this being made possible by the introduction of the gas at low temperature into the low and high compression cylinders sinmltaneously.

It will also be noted that the construction which I have provided is relatively simple in character. The double acting character of the compressor renders possible a substantial saving in parts andnraterials, and substantially decreases the floor space required for the machine. Also, the construction renders it unnecessary to employ complex and expensive packing boxes around the piston rod 8 in the partitions 17 and 18,-

it being obvious that these packings are required to Withstand only a low pressure. Moreover, leakage of gas past the partitions because of low pressure is reduced to a minimum.

- It will be observed that the compression process is relatively simple. consists of repeating in cycles a series of steps which may be designated as A, B and C in each cycle. Step A comprises trapping two volumes of gas from a low pressure source. Step B comprises the compression of the two volumes simultaneously into one volume. Step C comprises the compression of the one volume.

The apparatus may be so arranged that the first step ofone cycle is performed simultaneously with the last step of the pre ceding cycle, thus permitting a reciprocal means or itsequivalent to carry out the process, one stroke performing steps A and C, and the return stroke performing step 13. A further advantage of this overlapping arrangement of cycles results when two similar but independent processes of this nature are combined for operation by a single apparatus. Thus, while the reciprocal means performs steps A and C of one process, it may perform step B of the other process;

and while it is performing step B of the first process it Will be performing steps A and C of the second process. This permits each stroke of the reciprocal means, when such is The process 7 used, to perform all three steps A, B and C,

thus puttin an even load upon the appa- "atus at eac stroke.

While I have shown in Fig. 1 the lnlet ports 22 and 23 as communicating with a common source of supply through the pipe line 24-, these ports may if desired be connected to independent sources of supply 24? and 24" as shown in Fig. 2 because of the double-acting character of the compressor, the operation of each set of cylinders 77 or 77" being independent of the other set. By this arrangement it will be apparent that a single compressor is susceptible to use in a refrigeration system where it is necessary to return gases under different pressures owing to the necessity for maintaining 1n .difi'erent cooling chambers or cellars varying back pressures depending upon the temperatures to be maintained in such chambers.

It will be understood that the end cylinders 7 and 7 may if desired be water acketed, as indicated at their outer ends; and

c that the intermediate cylinder may be covered with a suitable insulation material 85 to avoidthe absorption of heat from the surrounding atmosphere of higher temperature.

I claim as my invention:

1. A compressor having, in combination with a pipe line, a plurality of cylinders each having a piston therein, means for reciprocating said pistons in unison, each of said cylinders having an inlet port whereby as the pistons move in one direction in their respective cylinders charges of fluid are drawn into the two cylinders, and means whereby in the next complete reciprocation of the pistons the charge in one of the cylinders is combined with the charge in the other one of the cylinders and the com bined charges are discharged into said pipe line. I 1 j 2. A compressor comprising a pair of cylinders, pistons in said cylinders having a common piston rod, one of said cylinders having a valve controlled discharge port at one end and an inlet port at its other end, a passage connecting the end of said one cylinder opposite said discharge port with the corresponding end of the other cylinder, and

a one-way valve in the piston of the one cylinder arranged to open in the direction of the discharge port. v

3. A compressor having a pair of cylinders, one of which constitutes a. high compression cylinder, pistons in said cylinders operatively connected together for operation in unison, the higl'i compression cylinder having a discharge port at one end and an inlet port at its opposite end, means con necting the end of the high compression cylinder opposite the discharge port with I the correspondingend of the other cylinder,

andv valve means in the piston of the high compression cylinder adapted as said piston moves away from the discharge port to.

permit the passage of fluid through the piston. V

- 4:. A compressor having a high compression. cylinder and a low compression cylinder, each having a piston therein and adapt ed to receive a charge ofgas or other fluid simultaneously as the pistons move in one direction, the low compression.cylinder be each of the end cylinders having an inlet port opening at the inner ends of their corresponding cylinders and communicating with a. source of supply, passages respective ly connecting'the inner ends of each of the end cylinders with the opposite ends of the intermediate cylinder, valves in the pistons in the end cylinders adapted to permit the passage of gas therethrough as said pistons move toward the inner ends of their respective cylinders, and valve controlled discharge ports leading from the outer ends of the end cylinders.

6. A double acting compressor comprising three axially alined cylinders each having. a piston therein, a piston rod rigidly connecting said pistons together for operation in unison, and means adapted as the pistons move in one direction to draw charges of fluid into the intermediate cylinder and one of the end cylinders and as the piston moves in the opposite direction to draw charges into the intermediate cylinder and the other end cylinder, said cylinders having connecting means whereby as the piston of the intermediate cylinder moves in either direction it simultaneously produces an inflow ot' tluid into one end of such cylinder from one of the end cylinders'anda discharge of fluid from the other end of said-intermediate cylinder to the opposite end cylinder,

three axially alined cylinders each having a piston therein, the end cylinders having discharge ports at their outer ends and the pistons in the end cylinders having valves adapted to permit the passage of gas there through in the direction of the discharge ports, and means operable in the reciprocation of the piston in the intermediate cylindcr to draw in a charge of fluid from one of the end cylinders and discharge a previous ly received charge into the opposite end cylinder, each of said end cylinders being in valve controlled communication with a source of fluid supply.

8. A compressor comprising a plurality of cylinders, pistons in the respective cylinders connected together for operation in unison, means operable as the pistons move in one direction. to draw charges into the separate cylinders, means including a portion oi? the last mentioned means adapted as the piston moves in the opposite direction to combine the charges in the separate cylinders, and means whereby as the pistons again move in their initial direction to permit the discharge under pressure of said combined charges.

9. A compressor having three cylinders each having a piston therein, means operatirely connecting said pistons together, and means providing passages for the flow of fluid ttrom two of said cylinders to the third cylinder and vice versa in the movements of said pistons, the arrangement being such that as the piston in the third cylinder moves in one direction a charge of fluid flows from one of the other cylinders into the third cylinder and simultaneously a charge of fluid previously received into the third cylinder is discharged into the other one of said pair of cylinders.

10. A compressor having a low compression cylinder and two high compression cylinders each of said cylinders having a piston therein, means operatively connecting the pistons together, and means providing passages connecting the low compression cylinder with the two high compression cylinders, the arrangement being such that as the pistons move in one direction a charge of fluid is drawn into the low compression cylinder and simultaneously a previously received charge is discharged into one of the high compression cylinders and as the pistons move in the opposite direction another charge is drawn into the low compression cylinder and the previously received charge is discharged into the other high compression cylinder.

11. A compressor having a low compression cylinder and two high compression cylinders each of said cylinders having a piston therein, means operatively connecting the pistons together, and means provid ing passages connecting the low compression cylinder with the two high compression cylinders, the arrangement being such that as the pistons move in one direction a charge of fluid is drawn into the low compression cylinder and simultaneously a previously received charge is discharged into one of the high compression cylinders and as the pistons move in the opposite direction another charge is drawn into the low compression cylinder and the previously received charge is discharged into the other high compression cylinder, the high compression cylinders having valve controlled discharge ports and the pistons in said high compression cylinders being adapted as they move in one direction to permit the passage therethrough of fluid discharged from the low compression cylinder and as they move in the opposite direction to force the fluid under pressure into the discluirge ports. 7

12. A machine at the class described roan prising two cylinders each having a piston therein and their corresponding ends in constant con'imunication, one of the cylinders having an inlet port and a discharge port and a valve-controlled passage through its piston, the arrangement being such that in one stroke of the pistons each. oi the cylinders receives a charge of fluid entering said inlet port, in another stroke the charges in the two cylinders are combined under ressure into the c 'linder havin the dis- 1 charge port and in a third stroke the combined charge in the last mentioned cylinder is discharged under pressure.

13. A compressor having two units each comprising a cylinder and a piston therein and each arranged to receive a charge of fluid in one stroke of their respective pistons, one of the units being arranged to discharge into the other unit in the succeeding stroke of the pistons.

14. A compressor having two units each comprising a cylinder and a piston therein and each arranged to receive a charge of fluid in one stroke of their respective pistons, one of the units being arranged to discharge into the other unit in the succeeding stroke of the pistons, and the other unit being arranged to discharge the combined charges in the following stroke of the pistons.

15. A compressor having two units each comprising a cylinder and a piston therein and arranged to draw in separate charges of fluid as the pistons move in one direction in their respective cylinders, and to combine said separate charges in one of the units as the pistons move in the opposite direction, the piston in the last mentioned unit also acting during its intake stroke to discharge a previously received charge under high pressure.

16. A double acting compressor comprising, in combination, a primary cylinder and two secondary cylinders each having a piston therein, means for operating said pistons in unison, means adapted as the pistons move in one direction to permit drawing charges of fluid into one end of the primary cylinder and into one end of one of the secondary cylinders, and as the pistons move in the other direction to permit drawing charges into the other end or the primary cylinder and into one end of the other secondary cylinder, said cylinders having interconnecting means whereby as'the piston or the primary cylinder moves in either direc 'tion it combines the two simultaneouslydrawn charges into either of the secondary cylinders wherein it is compressed on the succeeding; stroke of the pistons, and means permitting release of. the compressed fluid from the secondary cylinders.

17. An apparatus of the character described having, two means each including; a gas enclosure and each being adapted to trap a volume of gas, said two means being connected so that one is adapted to force its gas into the other, and the other is adapted to compress the combined. volumes.

18. A compressor comprising, in combination, a primary cylinder and a secondary cylinder each having a piston therein, means for operating said pistons in unison, means *adaptedxas the pistons move in one direction to permit drawing charges of fluid into one end of each of said cylinders, said cylinders haying interconnecting means whereby as the pistons move in the opposite direction the two charges are combined into the secondary cylinder wherein the fluid is compressed on the succeeding stroke of the pistons, and means permitting release of the compressed fluid from the secondary cylinder.

In testimony whereof, I have hereunto afiixed my signature.

JOHN M. SULLIVAN. 

